Lower Yafa, Lower Yafa'i (Arabic: يافع السفلى Yāfiʿ al-Suflā), or the Sultanate of Lower Yafa (Arabic: سلطنة يافع السفلى Salṭanat Yāfiʿ al-Suflā), was a state in the British Aden Protectorate. Within its area were the sheikhdoms of Al Saadi, Yaher, Kalad, Thi Nakheb, and Yazidi. It was a founding member of the Federation of Arab Emirates of the South in 1959 and its successor, the Federation of South Arabia, in 1963. It was ruled by the Al Afifi dynasty and its capital was at Jaar. Its last sultan, Mahmud ibn Aidrus Al Afifi, was deposed and his state abolished in 1967 upon the founding of the People's Republic of South Yemen and is now part of the Republic of Yemen.
Yafa is one of the biggest tribes of Arabia. The Yafai tribe is divided into 10 branches or sheikhdoms of which 5 are in Lower Yafa and the other 5 are in Upper Yafa. These sheikhdoms then are broken down to many smaller branches and extended families.
Yafa was also the seat of the ancient Himyarite dynasty, which lasted from 110 BCE to 632 CE when it was fully integrated into the Islamic empire.